This is a set of four items: two brand new and unopened, and two used. These are attachments for Meiji Hohoemi Rakuraku Milk. They can be attached to the Rakuraku Milk can for use. By attaching a Pigeon breastfeeding nipple, you can feed the milk directly from the can. This was very helpful when going out! The thickness is barely within the 3cm limit, so I plan to ship them as is in a paper bag with simple packaging.